The sum-rate capacity of a noncoherent memoryless multiple-access
Rician fading channel is investigated under three different categories
of power constraints: individual per user peak-power constraints,
individual per user average-power constraints, or a global
power-sharing average-power constraint. Upper and lower bounds on the
sum-rate capacity are derived, and it is shown that at high
signal-to-noise ratio the sum-rate capacity only grows
double-logarithmically in the available power. The asymptotic behavior
of capacity is then analyzed in detail and the exact asymptotic
expansion is derived including its second term, the so called
fading number. It is shown that the fading number is
identical to the fading number of the single-user Rician fading
channel that is obtained when only the user seeing the best channel is
transmitting and all other users are switched off at all times. This
pessimistic result holds independently of the type of power constraint
that is imposed.


Channel capacity, escaping to infinity, fading number, high
signal-to-noise ratio (SNR), multiple-access channel (MAC),
multiple-input single-output (MISO), multiple users, noncoherent
detection, Rician fading, sum-rate capacity.

-||-   _|_ _|_     /    __|__   Stefan M. Moser
[-]     --__|__   /__\    /__   Senior Researcher & Lecturer, ETH Zurich, Switzerland
_|_     -- --|-    _     /  /   Adj. Professor, National Chiao Tung University (NCTU), Taiwan
/ \     []  \|    |_|   / \/    Web: http://moser-isi.ethz.ch/

Last modified: Thu Mar 3 17:14:43 UTC+8 2011